Heinrich was never considered better than his father.
From birth, he always looked up to his father, spending every waking minute where he was, looking up to him. Heinrich was very much what a lot of people would call a "Daddies boy", wanting to be much like his father.
Heinrich never believed his love for his father to be unprecedented. He thought that his father was a great man, he was a Sanitäter (Medic) in World War II and contributed towards saving the lives of 67 people, which consisted of foes as well as allies. While his fathers methods were not very liked among his superiors, the soldiers working with him adored him, seeing as he managed to almost make people come back from the dead.
Heinrich always listened to his fathers stories, of how he was so great in WWII, of how he continued being a doctor afterwards.
These things motivated Heinrich to learn the history of Germany and made him adore the weaponry that was used in the war.
It also caused him to decide to follow his fathers footsteps.
He decided that he would also become a doctor, picking medical studies as his university studies. Heinrich had no problems mastering everything, he was very determined and also learnt a lot of information from his father beforehand.
Soon, after six years of hard work, he was awarded with a doctors title and decided to work in his fathers clinic in Hamburg. His father, seeing how his son worked to get close to him, decided to take Heinrich with him to a patient call in Chernarus, a retired Russian soldier lived there who was being periodically checked by his father.
They would arrive to the mans residence, only to find that the man was ravenous, with his skin decaying at a frightening rate.
The Russian soldier lunged at his father and ripped out his neck, leaving Heinrich in a panic, only narrowly escaping the rotting man by slicing his pocket knife into the mans throat.
From this point onward, Heinrich was alone, and he knew that he would have to move, seeing as this man was not the only one with this terrible disease.
With the shock of the situation and anger at the disease, Heinrich decided that he would decide to do one thing: Find a cure for this disease or an immunity for humans.
He shall avenge his father in the only way he knew how: Medically.